4 Easy Ways to Show the Critical Path in P6

1. Check the Gantt Chart

By default, the P6 Gantt chart will show your project’s Critical Path activities in bright red. This makes it easy to have a quick glance at the Gantt Chart et voila!, your Critical Path stands-out like a safety vest.

Hey! It’s not working! I don’t see any red Critical Path activities on my project. What gives?

Glad you asked. 😉 Maybe your Gantt chart looks like this instead.

Primavera P6, by default, uses Total Float to decide if an Activity is Critical or not. Activities with a Total Float value of 0 (or less) usually show red on the Gantt. If you have no red Activities, you may have a Must Finish By date set on your project. If your project is finishing earlier than the Must Finish By deadline, then you may not have any activities with 0 or less Float values which means there are no Critical activities.

2. Use the Critical Path / Longest Path Columns

Edit your columns and go digging for one called “Critcal” and another called “Longest Path”. Add one or both of these nifty columns to your Activity Layout to show clearly which activities are Critical.

3. Turn On a Filter

Using a Filter can also be a quick and effective way to manifest your Critical Path. Click the Filters button to turn on the Critical Path filter. This will show only the Critical Activities. There’s also a filter for the Longest Path.

4. Check the Schedule Log

Lastly, you can always check the P6 Schedule Log. The Schedule Log is a log file that gets updated every time your project is scheduled. Press F9 and make sure the box labeled “Log to File” is checked on. Then, click the “View Log” button to open the Schedule Log.

Once you have the log file open in Notepad, you’ll have to scroll down to the section labeled “Exceptions”. But you should see in the log a list of your project’s Critical Activities.

What Do You Think?

Which method works best for you in Primavera P6? Do you have your own method for finding your project’s Critical Path? Drop us a line in the comments.

About Michael Lepage

Michael is an avid project controls blogger and is the Chief Learning Officer here at Plan Academy. Michael has taught 1000s professionals how to use project controls software like Primavera P6 over the past 10 years through his online courses and tutorials. Michael is a member of AACE, the Guild of Project Controls and holds his PMP certification from PMI.

Comments

I’ve just tested the review of the Longest Path in P6 R7, and it would appear that the use of Level of Effort tasks completely renders the Longest Path calculations useless. LOE tasks and the final milestones are the only tasks which appear. Pity for those of us who use LOE tasks.

I have used Level of Effort with P6 EPPM 8.2 many times. It gives the LOE activities a duration dependant on other activities and removes te LOE activities from the critical path. However, they can be on the longest path. This makes sense to me, but I wouldn’t mind it if the LOE activities stayed off the longest path.

@Matt,
Strange – are there any lags in your LOE relationships by chance? I did some testing and I did find that my LOEs were on the Longest Path (not completely sure why). Are the tasks that your LOE is summarizing not on the Longest Path?

@Jose, yes and no. The screenshot in 2. shows which activities are Critical by the Total Float method (Critical column) and which activities are Critical by the Longest Path method (Longest Path column).

What is happening is that there are 2 ways to define what’s Critical. Yes, some activities on the Longest Path may not be considered Critical by Total Float. Thus, I recommend being aware that this is the case and being aware of the Longest Path.
M

Your lesson about critical path is really useful. But i have just one question. Can the Primavera programm calculate the duration of critical path or i have to do that manually. I cant find any command at P6. My definite target is to calculate the variance of Critical Path duration between the CP duration before and after levellling.

Hi Marios,
Put on the Critical filter, and make sure you have Grouping set to WBS. The Duration at the very top is the Duration of the Critical Path. To see the variance, you could create a baseline of your project before leveling. Assign the baseline to the project. Then, add a column to your view – “Variance – BL Project Duration”. This will be the variance after leveling.
M

Rajaram,
It’s probably because the mandatory constraint is forcing an activity to a date earlier than the network logic – thus breaking the network logic. The result is negative float on the mandatory activity causing it to be critical.
It’s a general consensus not to use mandatory constraints on any project. As they break the network logic, the integrity of your project’s logic is gone….and only with good logic can you have / track / manage your critical path. With broken logic, the critical path is uncertain.
The proper approach is to use non-mandatory or soft constraints and to monitor their effect on Total Float.
Hope that helps.

Due to many dependent activities and other conditions at site. schedules are not followed by the team as per the Base plan.
There are so many delays in schedule.
Kindly advice how to recover the delay by means of recovery plan / recovery schedule.

Jyothi, it’s pretty apparent that you will have to revisit all remaining work and re-plan it to build a recovery schedule. Look at your critical path and see if it makes sense. Work with contacts in the field to see if you can get the schedule to accurately reflect how the work will be produced. Talk to supervisors about the using the schedule daily – get support from management. It’s going to be a tough job, one that likely very frustrating. But the schedule is important.

There’s another possibility. If different calendars have been assigned to different activities, Primavera might not consider some activities with zero float as critical. Probably because the float is calculated in days while difference in calendar could be in hours (e.g. difference in workhours). It just happened to me.

How can I filter Resource assignment that are only assigned to activities on the critical path? I want to develop critical path S-curve

The only approach I can take to generate critical path s-curve is to assign resources to all activities on the critical path and use resource assignment weight to generate critical path s-curve. is there any other way?

Assign resources to all activities as normal – I assume you’re resource-loading your schedule. Go into Filters and turn on the Critical filter so only your Critical Path shows. Then goto View->show on Bottom ->Resource Usage profile and configure the graph to show your s-curve (cummulative curves).